Grin.exe crashes after a while. (win7, VM)

Hi,
I ’ have got the problem, that my grin node quits working regularly after some minutes or hours.
The text in the console window after crash is like:
[?1002h <- [?1002hl

It happens while Downloading Sync step 2/7.

I had similar problems with:
grin-v3.0.0-win-x64
grin-v3.1.0-win-x64
grin-v3.1.1-win-x64

I run the node In a Win7 VM in VirtualBox and it seems to be the same on different Host systems. Before the problems starts I had run the node already fully synchronized for a view days and then didn’t run it for a while. Maybe the problem has to do something outdated chain-state?

Does somebody know the Problem? So what can I do? Best regards.